Identify the correct pairs from the following with respect to the manufacturing techniques of different types of cement.

Type of Cement		Physical or chemical properties
1.	Quick-setting cement	Use of reduced gypsum content as compared to that used in ordinary Portland cement.
2.	Low heat cement	Use of reduced C2S content as compared to that used in ordinary Portland cement.
3.	Sulphate-resistant cement	Cement with C3A content not more than 5%

Explanation:

• Quick-setting cement is produced by finely grinding the cement and adding a small percentage of aluminum sulfate, reducing the amount of gypsum or setting retarder. The addition of aluminum sulphate and fineness of grinding are responsible for increasing the setting action of cement. It completes the initial set in 5 minutes and the final set in 30 minutes after addition of water. It is utilized to achieve the rapid strength within a short span of time (e.g. under water construction).
• Low heat cement or low heat port-land cement is a hydraulic binding material that releases low heat on the time of hydration. It consists lower percentage of C₃A (Tri-calcium aluminate) and C₃S (Tri-calcium silicate).
• Sulphate resistant cement is content < 5% tricalcium aluminate (C₃A) and <25% (2C₃A + C₄AF). This cement prevents sulfate attack on the concrete by minimizing the formation of sulphate salt.